I applied online and received an initial HR call the next day. The technical recruiter was nice and answered all my 'when and what' questions. Within the next few days, they set up a technical interview with a developer. They asked only one question, which I implemented with O(n) complexity. The interviewer seemed happy with the solution (though he may have been pretending, which is unprofessional). After a week with no reply from HR, I sent multiple reminders. I received an auto-reply email with a rejection and no feedback, even though my code ran and passed all test cases. Moreover, I asked the interviewer if he was looking for a more optimized approach, and he replied, 'No, that's the way to do it, I guess.' After a couple more emails, HR got back to me with the message: 'We have a very peculiar process; maybe your code wasn't organized or optimized, or you probably have less experience in the language you implemented the code in' (I had asked the interviewer multiple times if he was looking for any optimized code, and I have 3+ years of experience in the language I coded in). Regardless of how you answer the question, they reject you because, fundamentally, they are a 'happy company' that is not planning on hiring any candidates. It's a waste of time to attend these interviews. Basically, they don't respect your time.

Step 1

Throughout this interview, we'll pretend we're building a new analytical database. Don't worry about actually building a database, though – these will all be toy problems.

Here's how the database works:

• All records are represented as maps, with string keys and integer values.
• The records are contained in an array, in no particular order.

To begin with, the database will support just one function: min_by_key. This function scans the array of records and returns the record that has the minimum value for a specified key. Records that do not contain the specified key are considered to have a value of 0 for that key. Note that keys may map to negative values!

Here's an example use case: each of your records contains data about a school student. You can use min_by_key to answer questions such as "who is the youngest student?" and "who is the student with the lowest grade-point average?"

Implementation notes:

• You should handle an empty array of records in an idiomatic way in your language of choice.
• If several records share the same minimum value for the chosen key, you may return any of them.

Java function signature:

java public static Map<String, Integer> minByKey(String key, List<Map<String, Integer>> records);

Examples (in Python):

python assert min_by_key("a", [{"a": 1, "b": 2}, {"a": 2}]) == {"a": 1, "b": 2} assert min_by_key("a", [{"a": 2}, {"a": 1, "b": 2}]) == {"a": 1, "b": 2} assert min_by_key("b", [{"a": 1, "b": 2}, {"a": 2}]) == {"a": 2} assert min_by_key("a", [{}]) == {} assert min_by_key("b", [{"a": -1}, {"b": -1}]) == {"b": -1}